When the financial crisis occurred, not only did property values plummet, but the rental market crashed as well.

In this case I don't see the harm in delaying the closing, since the seller can't meet the terms of the contract, unless there's some financial harm to you (higher interest rate, etc).

Depending on how many years ago the revaluation occurred may give you a hint of perceived valuation, but it's not a current valuation/appraisal. 

LLC meeting minute with dates etc,  Undercapitalization occurs when a company does not have sufficient capital to conduct normal business operations and pay, or not enough cash flow, unable to access forms of financing its change of bankruptcy is high by not servicing debts etc. 

For naturally occuring rehabs/updates I expense out the materials through the real estate buisness and take no wage.

That being said, it's often a take it or leave it and if the deal is that good, with a good attorney review for anything that could really harm you (like no inspections or title search allowed, as examples) then you have to make the business decision. 

The more you lose money, the longer it takes you to turn a profit, since a profit only occurs after you break even on the cash you put into a deal.

I often break it down into the "five pillars" of protecting your assets.1st pillar is avoiding unnecessary and risky activities (don't drink and drive, insurance generally won’t cover your poor decisions) and take good care of your investments - these simple steps will help you prevent lawsuits before they even occur.2nd pillar is a good insurance policy as that cover the majority of your exposure.

Can't find the podcast either...Now I'm very new to 1031 so I have no idea how the actual details of that could occur or what had to actually happen.

Have you actually had a period of time where you have been "bombarded with unqualified tire kickers", or are you just assuming that would occur?